Fluid pressure breaking mechanism for mining machines



June 9, 193i. E. c. MORGAN FLUID PRESSURE BREAKING MECHANiSM FOR MINING MACHiNES 5 Sheets-Sheet 1 Filed June 12, 1929 MW w m u e n a M m 3 W mm T I ah. mu mm. z NM 0 .a 0 Pl i H .w wH.H WWW n i Nu m I.

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' Arroe/myd June 9, 1931 E. c. MORGAN 1,809,307

FLUID PRESSURE BREAKING MECHANISM FOR MINING MACHINES Filed June 12. 1929 a Sheets-Sheet 2 347%4 D. K =1 5 .I NM R N m m 4 %E E m M Q QQQ m m m N g N gr N mum M 5/ r n V K U M 7 M m .4? mm& v M Wm MM m N y z A N E v g x H l .u l m\\\ i E Q3 M M M W m June 9, 1931.

E. c. MORGAN Filed June 12. 1929 3 Sheets-Sheet 5 Patented June 9, 1931 EDMUND oi OR AN, DECEASED, LATE on NEW ORK. N. Y., BY OLIVE EIYTGENIIE MORGAN, EXECUTRIX, on NEW YORK, N. Y. I

' FLUID .IPB-ESSUHE BREAKING MECHANISM FOR. MINING MACHINES 'Appheati'on filed June 12,

' The invention relates to apparatus operated by fluid pressure to dislodge material in a mine and-is particularly adapted 'for use in miningmachines for mining coal. Oneoftheobjects'of the invention isthe provision of an; improved and 1 eflicient expansible breaking; deviceadapted to-be inserted in a kerf in a mine vein and operated by fluid pressureto dislodge material from the unmined mass. I l A' further object of theinvention is the-provision of interior self-restoring mechanism for anexpansible fluid pressure operated breaking device. I A further objectof the invention'is the provision of apparatus for exerting fluid pressure suddenly on the expansible breaking device adapted to be inserted into an'incision inamine wall. I A further object is the provision of improved and eflicient automatic controlling mechanismfora hydraulically operated expansible breaker adaptedjto be inserted in a kerf in a-mine wall. l I

A still further objectof the inventionis the provision of a plurality of breaking devices independently connected to separate :impulseproducing devicesf I I Other objects'of'the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims. Referring to the accompanying drawings: Fig. 1 is a'sectional' elevational view illustrating the automatically controlled-hydraulic mechanism for-transmitting pressure to hydraulicbreaking devices;

- 2 is an elevation'al V16WOf an upright kerf-cutter showing the application of-hydraulic breakers to a mining-machine for operation in a 'kerf produced by such -mining machine; i "Fig. 3 is a plan viewpartly in-horizontal section of'a plurality :of hydraulic impulse producing devices; i Fig, 4 is a sectionalpview' on theline 4-4 of Fig. 3,'-looking in. the direction of the aITrOWIS; "*1 x Fig. 5 is asectional view'of Fig. 3 on the line 5-5, looking in the direction of the arrOVS; .Y 'L-'.'

1929. Serial No. 370,431.

Fig. 6 is a sectional elevation taken through line a a looking inthe direction of the-an Fig. 8 is a sectional viev on the line a'-a of Fig. 6, looking in the direction'of the arrow 3; I

' Fig. 9 is an elevational view of amodification of the removable plunger of Fig. 6;

Fig. 10 is a sec'tionalelevation on'the line 10 1O of Fig. 9; l r

Fig. 11 illustrates a modification of the structure shown in Fig. 6; and k i Fig. 12 is a diagrammatic view in sectional elevation of a modification of the valve structure shown at the right-hand portion of Fig. 1.

Referring to Figs. 6, 7and 8,'which show the type of hydraulic breaker particularly adapted for use in connection with'kerf-cutters in mining machines as shown in Fig. 2, it will be seen thatthis breaker comprises two principal elements relatively expansible. One of these elements is in the form of a shallow cup as shown at 13 in Fig. 6. The other ele- 'ment'll is in the form of a'disc adapted to fit in the cylindrical recess 15 of the casing 13. The disc 14 is movable axially relatively to the casing 13 and therefore in effectconthe material between the kerf 19 and a kerf 1 distant therefrom toward the left as viewed in Fig.6.

The shallow cylinder 13 as well asthe plungerli are rela-tively'thick and of ma+ terialto give them considerable strength for action ina hydraulic breaker of theiexpausible type. The cylinder 13 may lie-rigidly secured to thekerf-cutter frame 20 shown in F 1g; 2, or the cylinder 13 may beins'e'rted through a-circular opening in the kerf-cutter frame 20 so as to leave an annular space 21" between the frame '20 and the cylinder 13, asshown in Fig. 6. In that event the pipe 22 extending through a strap 'QS, as shown I in Fig. 2, may be relied upon tosupportthe hydraulic breaker in proper position in the circular opening in the kerf-cutter frame 20.

The pipe 22 may also be secured by an additional strap 24 to the kerf-cutter frame 20, as shown in Fig. 2. Preferably the pipe 22 passes by the cutter-chain 25 on the inside or distant from'the solid mine wall 17 shown in Fig. 6. This iseifected by extending the pipe 22 through an opening 26 in the kerf-cutter frame 20. In a similar manner an additional hydraulic breaker 13, 14 may be mounted at the lower portion of the kerf-cutter frame 20, as shown in dotted lines in Fig. 2. The pipe 22' is extended through a bracket 23' and thence through an opening represented bythe oval dotted line 27, in order that the pipe may be secured. by the strap 28 to the inside surface of the frame 20.

i The type of hydraulic breaking mechanism shown in Figs. 2, 6, 7 and 8 is particularly applicable to the two upright spaced-apart side kerf-cutters shown inthe Edmund C. Morgan Patent No. 1,116,356, granted November 3, 1914, for coal mining apparatus. It should be understood that one or more of such hydraulic breakers, may be mounted upon each of the upright frames of the respective spaced-apart kerf-cutters within the boundaries or path of travel of the chain cutters, as shown in Fig. 2 of the drawings in the present application.

' lVhen fluid pressure is exerted through the passage 29 the plunger 14, shown in Fig. 6,

'may be forcibly moved out to the dotted line position 16 while the cylinder 13 rests firmly against the unmined mass 17 thereby effecting the breaking down of the coal 18. Therefore, when spaced-apart upright kerfcutters areprovided with such hydraulic breaking devices such as that shown in Fig. 6 the plung-ers 14 should face toward each other so that the opposite breaking devices will move toward each other to break down the material between the kerfs.

In order to limit the outward movement periphery of the plunger 14 parallel to the axis of the-latter. This slot 32 terminates short of the inner surface of. the plunger 14 so as to leave an abutment 33 to engage the key 30 andithus limit the outward movement is a section 7 6, looking in apart as to receive a wrench shown in the direction of the arrow 2, the parallel dotted lines adjacent the section line indicating the hidden edges of the circular opening in the plate 20. Fig. 8 is a section of Fig. 6 on the line aa, looking in the direction of the arrow 3. It should be noted that the annular portion 39 is the annular seat on the plunger 14 against which the annular packing 36 rests when secured in position. It should also be noted that the ring 34 is providedwith a cylindrical portion 40 in position to contact with the bottom 41 of the cupshaped recess or opening in the frame 13.

The opposite end of the spring 42 is provided with a diametrical extension or latch 47 as shown in Fig. 8 which is a sectional View on the line aa looking in the direction of the arrow 3. Bolted to the inner face or in ner cup shaped central recess 48 of the plunger 48 are two sector plates 49 and 50 each provided with offsets to form keepers 5land 52. The. plate 49 may be secured in place by means of the bolts 53 and 54, and the plate 50 may be secured in position by means of the bolts 55 and 56. As shown in Fig. 8, the sector plates 49 and 50 are spaced-apart to form a slot between them of suflicient width to permit the free insertion therein. of the diametrical extension or latch 47 of the spring 42.

After the spring 42 is secured to the bottom 41 of the cylinder 13 by means of the construction shownin Fig. 7 and at the righthand central portion of Fig. 6, the plunger 14 may be inserted into the cylinder 13 by sliding the piston packing 36 along the cylindrical surface 15. The plunger 14 may then be adjusted in position until the spring extension or latch47 shownin Fig. 8 fits in the slot 57. A spanner wrench may then be insertedin the recesses 58 and 59 in the outer flat surface of the plunger 14 and the latter turned relatively to tue cylinder 13 in clockwise direction, looking from left to the right in Fig. 6, so that the extension or latch 47will-move under the offsets 51 and 52 and so that the latter will act as notches or cavities to lock the plunger 14 to the spring 42.

In lieu of the spaced-apart diametrically arranged recesses 58 and 59 in the outer flat surface of the plunger 14, the spaced-apart recesses 60 and 61 shown in Figs. 9 and 10 may be provided of such shape and distance 0- sition in dotted lines 62 in Fig. 10. Siibh spaced-apart recesses 60 and 61, especially adapted for receiving a wrench, may be provided in addition to the spanner recesses 58 and 59, and in any event such recesses are preferably located symmetrically with respect to the center 63 of the plunger 14.

vWVhen the plunger 14 is inserted the key 30is disconnected from the cylinder 13.- The position of the slot 32 in the plunger 14 relative. to the keyritselfenables the operator to readily determinewhen the spring-extenslon or latch47 is in proper position to enter the slot 57, and after theslot '32 has heenturned to receive'the key 3.0,.the latter; will lock the extension 47 against. turning movementrelas tively to the keepers 5,1 and52. i It will "thus be seen that thekey 30 and the slot32 not only form limit stop mechanism for the plunger 14 but also lock the plunger 14 in the posi tion Where the extension 47 is under theoifsets 51 and 52 as shown in Fig. 8. The spring is eifectively andfentirely enclosedin a. very compact manner within-the space which receives the. pressure medium and therefore the operation of the spring is not interfered with by coal 'dustor other extraneous -material. The spring acts. automatically-to res termittently operated while the mining'machine is continuing its forward feedingmovements.

Moreover, whenever; desired, for, repair,'

cleaning or otherwise-,-the key 3.0.1nay be re,- moved and the plunger ll 'turned ail'ltliClOCkwise to release the same from the spring 42 so that such plungermaybe Withdrawn from thecylinder 13-, i Fig; 11 shows aimodificationof the structure-shown in Fig. Gin that the dimensions are smaller with respect to'therdiameters and the. springmay be releasedor secured-inlposie tion by the turning ofv exposed. nuts. 5'5 The pressure pipe 22 is. connected to the cylinder gso as tocommuriicatewith the;interior.- of

chamber 6.6. which is providedwith a cup.- shaped or cylindrical recess 67 in which fits the plunger orpiston 6.8ihavingan "annular packing v69 Secured to the. inner end thereof by means-of screws 70 and .71.. lA'strong spring "('2 fits in acylindrical chamber- 73,-theconvolutions of the. spring: being incontactw-ith each other so, that this spring may act as :an expansion spring to restore 'the plunger:68 to its initial positionw-hen the'pressure medium i'n the'chamber 66%isfwithdrawn. One

end ofnthe-spring 72 is -.screw-threa.ded. at 7 l to receive arnut 75 which islocated in a recess in the outer surfaceofthe'plunger68; It will be seen. that the screw-threaded'endfi 4 10f the spring 7.2 passes. through :the centerlof the outer-portion of the plunger 68; Y

The other. jscrew-threaded end' 76 0f the spring '72passes" through-1 the center 'ofthe bottom: ofthe cylinder 65andreceivesa nut 7.7 i inthe recess 78.: A conically-shapedpro- 7 jectionor spearhead 7 9 maybe screw-threadfed at 8.0 into the recess in'which-the nut'75 is located. This conical projection may be added to the plunger 68 when desired to form trating the kerf cutmaterial such asthat shown at18-in Fig. 6 while'the bottom 'of'the cylinder 65 rests against the solid unmined mass such'as that shown at 17 inFig. 6.1 Sucha pointe'd' instrument'79 will assist r inv initially splitting the materialthus. assisting inbreaking' it down and dislodging-it from the unmined mass between thespaced apart upright si'de kerf-cutters and abovethe undercutting 'kerf-cutters. V

' a-pointed instrument or, spear-head for penek I Referring now to Fig. '1,"the apparatus for producing fluid pressure in suchhydraulic breakersas those shown in Figs. 6- andyll will be described; Mounted on the'stationary j frame-81- is a hydraulic cylinder 82 along which is"longitudinally movable a plunger 83 for: forcing the pressure medium 84'into'the of gearing 86'to the hydraulic pump 87; By means of this pump the liquid is um ed from the tank'8'8 through the pipe 89intothe pipe 9-0 and thence into the cylinder 82. From thecylinder82 the liquid is passed through the pipe 91 into thepipe 22 whenithe valve '92is in the positionshown in Fig. 1'. By

means ofthis electrically operated hydraulic pump. -,pressure may be exerted through the pipe' 22 intojthe' hydraulic breaker'to move theplungerthereofrelativelyto thecylinder i. f

against the'action of theie'xpansion spring W thin the breaker. This" operation is comparatively slow,'however, and therefore adfd tionalinechanis'm has been provided i for securing comparativelyquick action of the plungers and thereby effect hammer-blows of said plungers on the material to be broken down; When. 'the breaker is operated by to pipe '22 and-thence to the hydraulic breakers. Anelectric motor is' connected by means means of the pump mechanism alone it may be automatically restored e; initial position V f j i by turning the valve 92' so- "that the pipe 22 will communicate through "the valve'92 to the tank-88. Thespringwithinthe breaker willthen restorejthe plunger" to initialposition and cause the pressure-medium"therein to flow back through zthefp'ip'e 22 into the-tank i 88. ,Thelattermay be provicled with ascrewa threaded cap 93 to close a filling opening .-f ,p Thefapparatushforproducing thehainmen' blowaction 'comprise'salarge ICyIiHder'QIfin I W" clr'fits a piston95connected to afpiston I25 rod 9fi coupled'at 97' to the' plunges-83.3 A

[ spring 98 is located between one 'end of the air pressure cylinder '94 'andthe piston 95 a back of the latter. This spring tends'to fforcef the'piston 9.5 and thePlungerSS toward 'the' I left but whenthepelectric motor 9.9 operates the gearing 100, theair pump 101 will force air under compressioninto the cylinder 94, thereby moving the piston 95 toward the right against the action of the-spring 98 un- 'til the collar-102secured to the piston rod 96 engages the lever 103 and swings the latter on itspivot 104. at the upper end of the bracket 105 -which is mounted on the frame 106.

- JSWingingof .the lever 103 to the right will causeits arm 107 to transmit upward movement to the spring 108 to lift the switch lever 109 and close the switch 110. Closing of the switch 110 .willconnect the positive and negative mains through the electro-magnet 111 and-themotor; 85. The electro-rmagnet 111 will retain the switch 110 in closed position even after the electric motor 85has operated froin the electric motor. 85 and thus automatically stop the operation of the pump 87.

'lhemotor for the air pump is also auton'iatically controlled. Whenever the air pressure in thecylinder- 94 is suflicient to hold the piston 95 to theright, as shown in Fig. 1, the air pressure exerted through the pipe 113 into the auxiliary cylinder 114 will move the piston115 and piston rod 116 to theright against the action of thespringv 117. Thepiston rod l16is pivoted at itsrighthand end tolthje lever 118 which is pivoted at119-to. the frame 81. Also pivoted at 119 for movementzrelatively to the lever 118 is a switch lever 120 which. is connected by a spring 121 to an arm 122 extending from the lever'f 1 18.

Vhen the pressure within the cylinder 94 falls below a predetermined amount, particularlywhen the coupling 97engagesthe lever 103, the spring 117 will move the switch lever 120' tojthe dotted line positionand thereby cause theclosure of the switch 12 3. The elec tr'oma'gnet 124 will then be energized to hold theswitch123 in closed position andthe circuitf through the,n1otor 99 wills be closed to cause [the operationofthe air: pump 101;

When the air, pressure in the cylinder 114 is sufficient toinove the piston 115 to the right av sufi'icient distance to cause thefinger 125 to engage l. the; switch, lever j 120 and move the latter to the left-, the switch will be automatically openedv and the current, automatically cut off from the. motor 99ftoelfectan automatic stopping of the operation of the air pump 101. V From the foregoing'it will be seen-that considerable air pressure may .always be maintained on the piston 95 tendingto move the plunger 83 to the right. Therefore, whenever thevalve 92 is opened to establish communication between the cylinder 82 and the pipe 22, the air pressure accumulator will actvery quickly to cause the flow of the liquid from the cylinder 82 through the pipe 22 into the hydraulic breaker whether the pump 87 is operating at such time or not.

When the valve 92 is opened and 'said hammer-blow on. the hydraulic breaker is effected, the plunger 83 will move to the right. l/Vhen the plunger 83 has been moved to the right to the position shown in Fig. 1, the switch 110 will be closed and the motor 85 automatically started to operate the pump 87 and produce suflicient pressure in the cylinder 82 to again move the plunger 83 to the left, until the coupling 97 effects the opening of the switch 110 and the stopping of the motor 85 which in turn stops the pump 87. It will thus be seen that while the hydraulic pump supplies the pressure on the liquid in the cylinder82 the quick initial operation of the hydraulic breaker depends primarily on the air pressure accumulator. The apparatus therefore operates automatically to effect a quick hammer-blow initially which may be supplemented automatically by the operation of the pump when the plunger 83 moves a suiiicientdistance to the right, as viewed in Fig. 1. l l

The greaterthe number oftimes that the hydraulic breakers are operated, the more often must the hydraulic pump 87 be automatically operated to restore the pressure in the cylinder 82. During normal operation the piston 95 may occupy a position intermediate the ends of the-cylinder 94: where the collar 102 and coupling 97 will be equally spaced from the lever 103. After the hydraulic breakers have been operated a number of times the collar 102 will engage the lever 103 to effect the starting of the pump 87 and when pressure has been restored sufficiently in the cylinder 82 the coupling 97 will engage the3lever-103 and cut off the current from motor 85. After this occurs the hydraulic breakers may still be operated by the air pressure accumulator until there hasbeen su'lficient'flow of the pressure medium 84 from thecylinder 82 to cause the collar 102 to engagethe lever 103 and close the switch 110. The entiresystem isautomatic and under the controlof an operator who merely manipulatesthe valve '92'. i I

It should;be.notedthat when desired the hydrostatic'expansible deviceshown in Fig. 6' maybe operated so as to be expanded to a limited extent where the bottom of the cylin der 13 and the outer. faceof the plunger 14 will engage the walls '17 and 18 of the'kerf and slide along the same during the feeding operation of'the kerf-cutter shown inFig. 2. After the 'expansible structure shown in Fig.=6 has been expanded'to a limited extent I v so asto act as aspacer it may be locked in 22. As the feeding operation continues and the expansible device slides along thewalls of the 'ker'f, thekerf is keptopen by preventing the Walls 17 and-18 from moving toward each other and therebyybinding of the 'kerfcutter in the kerf is prevented and free feed ing movement of such kerf-cutter is facilitated. VVhenever desired the VEIVQ'QZHIELY beoperated to secure the breaking down operations hereinbefore-mentioned.

InFig. 12 is shown a modification of the valve 92 of Fig.1. =The-fulll line position of the valve 92 is;obtained when the lever foroperating this valve occupies the position in-,

dicated by the dotted line126. 'COfIllDllIllcation will then be established between the medium such as water.- Now, if the lever is turned to the position shown at "127 the plunger 83 will tend to move rapidly toward the right and then if the lever is turned back to the position 126 the continued movement of the plunger 83 will cause a hammer-blow to be exerted on the plunger of the hydraulic breaker. Whenthe operating lever :is turned 7' to the position shown at 129 the breaker will "be automatically restored to initial position. It should also be notedthat the operating As shown in lever may be turned to establish communication between the pipes9-l and .22 and then quickly moved tothe; position shown atj129 to establish communication betweenthe pipe 22 and the pipe 128. ldhirthermore, whenever it IS desired to effect the. operationof the pump 87, the position127 could be ef-l fected so that the. plunger 83 would move to the right until the lever 103 closes the'switch 110 and starts the motor 85. V

In Figs. 3, v4, and5, isshownamodification of the structure shown-- in Fig. 1, in that sepa! rate 1 cylinders 1301and 131 are provided ;in

stead ofthe singlecylinder 82of Fig. 1.2 In

this manner independent control of the pres sure: mediumthrough the pipes 22 and 22 leading to hydraulic brakers is obtained, one

locatedon one upright side kerf-cutter andv restricted to the-precise construction; herein connected by a coupling 97 totwo spaced apart plungers 1'32, 133, respectively movable in the cylinders130 and 131, which arelocated in acasting 1 34secured' tothe frame 81. Leading downwardly from the righthand end portions of thecylinders 130 and 131- are pipes'i135 and 136 in which valves 137 and 138 are located,lthese valves being 131inthesame manner that the pipe -leads- V upwardly fromthecylinder 82 inFig. 1; s

This may be seen by referring to Fig. 4 which is a sectional elevation of'Fig.- 3 on theline 4+4, looking in the direction of the arrows. i

. Fig. 5 isasectionalelevationof Fig.3 lookarrows-or from -0 1 9' ing inthe direction of the right and left. 7 7 a I It should also be understood that the-kerfcuttershown in Fig.2 may be mounted on a long, wall machine or on I any other. type iof kerf-cutter. making a'ker'f spaced back from the face of .themine wall so thata hydraulic breaker'mounted-on the frame ofthe kerfcutter may act to exert pressure toward the free face" to dislodge coal from theunmined mass In other words the breaking m echa nismherein'disclosedis adapted to be mount ed onfa kerf-cutter which forms a kerf in a mine wall spaced fromthefree. face or working face of the'coa-l. The breaking mechanism will then constitute hydrostatically actuated' means carried by the. kerf cutter to exert pressure toward such free. face to dis-v lodgethecoaL,

1 Obviously those skilledin the art may make various'changesinthe details and arrange- I mentsof parts'hereindisclosed without departing fromthe spirit andscope of. the in vention asdefined by the claims heretoap I pended and it iswished. thereforenot to be disclosed.

Having thus fullyzgdisc'losed an embodiment of the inventionywhat is desired to be secured, by Letters Patentyof the' United 7 Statesis: V

1. In aobreaking device,the--combination with a cylindernof a, spring adaptedrtof-be located within said cylinder;=-means for se 1 curingoneend ofsaid spring to thebottom of saidfspring for detachably securing said I plunger tosaidspring.

y 2. A v breakingdevice adapted to be inserted in akerf in amine wall and comprising a cylinder and a plunger, an enclosed spring having one end connected to-the cylinder and the other end detachably conected to said plunger, means. on the plunger adaptable, said cylinder and plunger having diametrically arranged pressure-exerting surfaces adapted to act onopposing walls of an incision in a mine vein, means for directing a fluid pressurem'edium into said cylinder, means'for limiting the movements. of said plunger relatively to said cylinder, and a pull,- ing spring enclosed by said cylinder and plunger for restoring them to relative retracted positions. I

i 4. The combination with a skerf-eutter adapted to. cut an upright kerf in-a mine vein, of an expansible dislodging device comprising a cylinder and a plunger mounted on said kerf-cutter to, move bodily therewith into the kerf cut thereby but operableindependently of the feed of the kerf-cutter, means for directing a fluid pressure medium into said cylinder, means for holding'said dislodging device in anopening in said kerfcutter for limited bodily rectilinear move lnent' relatively to the latter at right angles to the kerfwalls with the outer surface of the plunger bearing against one wall of the kert' and the inner surface of the plunger bearing againstthe other wall of the kerf, and means for controlling the expansion of the plunger from the cylinder so as toact without substantial strain on the kerf-cutter but independently thereof. I

5. The combination with a kerf-cutter comprising a frame, of a breaking device comprising a cylinder and a plunger mounted on said frame, means for operating said breaking device, a spring connected between the bottom of the plunger and theboitom of said. cylinder for automatically restoring said breaking device to its initial position relative to said kerf-c'utter upon discontinuance I of the operation of said breaking device, and

means operable by. turning the plunger relatively to said cylinder to release the spring connection between said plunger and cylin derand permit detachment of the plunger.

6.- A fluid-pressure-exerting device adapted to beinserted into a kerf in a mine wall,

comprising a cylinder and a plunger with a pullingrestormg spring enclosed, thereby, said spring being connected at its ends to said cylinder and plunger to collapse the latter when the pressure medium within is released, the connection at one end of said springbeing detachable, and means on the plunger to receive a spanner wrench to turn the plunger relatively to the cylinder to release the detachable end of said spring to enable withdrawal of the plunger from the cylinder. I 1 7 In a breaking device, the combination with a cylinder, of a plunger therein, a'spring having one end connected to said cylinder and the other end to said plunger and entirely enclosed by said cylinder and'plunger, and means for securing the ends of said spring to said cylinder and plunger, said means being inaccessible through either the plunger or the cylinder; V

8. In a breaking device, the combination with a cylinder,o'f a spring having one end secured to the interior bottom of said cylinder,'a plunger, and a detachable connection between the other end of said spring and the inner-wall of said plunger without any extension through the plunger.

9. In a breaking device, the combination with two relatively movable members, of a spring'eiiclosed bysaid members, a permanent connection between one end of said spring and one of said members, and latch mechanism between the other end of said spring and the other of said members adapted to be released by the relative turning of said members.

10. expansible breaking deviceadapted to be inserted into a kerf in a mine wall and comprising relatively movable members each imperforate'throi'lghout, a restoring spring entirely enclosed 7 within said expansible breaking device, and connections between the ends of said spring and said members tending to pull the same together to initial position.

11. An expansible hydraulic breaker adapted to be insertedinto a kerf in a mine wall and comprising a shallow cylinder, an imperforate plunger in said cylinder and movable relatively thereto, a spring within said cylinder and having one end connected thereto, and'a' detachable connection between the other end of said spring in the inner side of said plunger.- Y 12. An I expansible hydrostatic breaking devicecomprising a cylinder and a plunger, a-springwithin said'cylinder and having one end secured thereto, latch mechanism between the other end of said spring and the inner side of said pliingensaid latch mechanism securing said plunger tosaid spring ,7

when the plunger is turned from one predetermined position to another predetermined position, and means for preventing the plunger from turning away from the lastnamed position'to effect locking of the latch mechanism. a r

- "13. An ex'pansible breaking device 'comprising relatively movable members, a pulling spring within the breaking device for restoring the parts thereof to initial position, a detachable connection between one end of said spring and one of said members, said I connection'bein g detachable byturning one member relatively to the other, and a-key on one member extending into a slot in the other member to prevent relative turning of the members to holdthe detachable end of said spring locked to the members to which it is connected.

14. Anexpansible breaking device adapted to be inserted into an incision in a mine wall and comprising a cylinder, an imperforate plunger a pulling restoring spring secured at one end to the inner bottom of said cylinder, and a detachable connection between the other end of said spring and-the inner wall of sa1d plunger without accessibility from' same against the action of said spring, and

means for controlling the flow of the pressure medium to effect expansion of the' device to a limited extent when it is to act as a spacer to prevent binding of thekerf-cutter in the kerf and to also cause said device to expand to a greater extent to break down material adjacent the kerf. I

16. In a breaking device, the combination with a cylinder, of a spring adapted to be located within said-cylinder, means securing one end of said spring to the bottom of said cylinder, a plunger movable in said cylinder, spaced-apart keepers with a slot between them on the inner wall of said plunger,v

and a transverse extension on one end of said spring adapted to fit in said slot in posltio-n for, said keepers to move over the same to detachably secure the plunger to said spring.

17. A breaking device adapted tribe inserted into a kerf in amine wall and'co-mprising a cylinder and a plunger, an enclosed spring having one end connected to the cylinder, a connection eiiectedbetween the other end of said spring and the inner Wall of said plunger by the turning of the latter rela-. tively to the cylinder, means on the plunger to receive a turning tool "to connect the plunger to said spring, and means for look ing the plunger against turning relatively to said cylinder after said plunger has been connectecl to sa1d spring as aforesaid.

18.- An expansiblc breaking device com prising a cylinder and aplunger relatively movable, sa1d cylinder andplunger havlng pressure exerting surfaces adapted to act on opposing walls of an incision in a mine vein,

means comprisingja key and slot between said plunger and said cylinder for preventing relative turning of the plunger and cyl I inder, and an abutment in position to be en-' gaged by said key for, preventing the plunger from moving out of said cylinder.

19. An expansible breaking device com prising a cylinder and a plunger, a restor-' ing spring having one end connected to the bottom wall of the cylinder, a detachable connection between the other end of said spring and inner wall of-said plunger, means comprising a key and slot for preventing turning of the plunger relative tot-he c-ylin der to lock, the plunger connected to the spring, and an abutment in position to engage the key to prevent theplunger from moving out of the cylinder.

. 20. An expansi-ble breaking device comprising a cylinder and a plunger, a. pulling restoring spring enclosed by the cylinder and plunger, a detachable connection between one end of, said pulling spring and the inner wall of .the'bottom of thecylinder, a detachable connection between the other end of said spring and the inner wall ofsaid plunger,

said lastnamed detachable connection being releasable by turning. the whole plunger relatively to the cylinder, and means for preventing turning of the plungerrelatively to the cylinder to lockfthe plunger connected tos'aid spring. 21. In a mining machine, the combination with a ker'ficutter comprising a cutter frame and an endless cutterchain mounted thereon, of an expansible pressure-exertingdevice adapted to move therewith into the kerf out p by said kerfcutter, said pressure-exerting device comprising telescoping cup-shaped pressure-exerting ,plun gers movablein oppo frametransversely thereof, and a spring besite directions each relatively to said "cutter 1 tween said plungers, means for operating said kerf-cutter including feed thereof while moving sa1dpressure exert1ng device along between said source and said device to trol the operation oftheflatter.

In testimony whereof "I have signed my name to this specification June, A.-'D.'.1929. r I OLIVE EUGENIEMORGAN, Emecutrix of the Estate of Edmund 0;

,Morgan, Deceased. i a

con-

lie

the kerf'cut by said kerf-cutter, a source of fluid pressure supply for said pressure-exert-v V mg device, and a valve for the connection onthisSth day f; 

